While primary root canal therapy is an established treatment with good levels of clinical and radiographic success outcomes are not always favourable. If this is the case the options are, non-surgical retreatment, surgical endodontic treatment of extraction and/or replacement with a dental implant.

The aim of this study is to evaluate and compare the clinical and radiographic outcomes of nonsurgical root canal retreatment and endodontic microsurgery.

Methods

Searches were conducted in the PubMed/Medline, Embase and The Cochrane Library databases. Human clinical studies with a minimum sample size of 20 teeth and 6 months follow up that had clinical and radiographic assessment of success/failure were considered. Only English language papers were selected. Three reviewers screened the studies and quality assessed using a 10-point checklist. Weighted pooled success rates and 95 % confidence interval (CI) estimates of the outcome were calculated.

Results

18 studies involving 2373 patients were included.

There were 11 studies on microsurgery (1175 patients) and 7 on retreatment (1198 patients)

6 of the retreatment studies were prospective, one retrospective.

4 microsurgery studies were RCTs, 3 prospective and 4 retrospective.

The outcomes for each group were pooled separately.

There was a statistically significant difference was between the weighted pooled success rates for the microsurgery group and retreatment group. This was apparent in all follow up periods except those greater than 4 years.

Conclusions

The authors concluded

Based on this study, endodontic microsurgery was confirmed as a reliable treatment option with favorable initial healing and a predictable outcome. Further long-term clinical studies investigating endodontic microsurgery and retreatment are needed in the future.

Commentary

As the authors highlight at the beginning of their discussion this review does not provide a direct comparison between these two approaches of managing a failed root canal treatment. Each of the approached have been combined separately to provide a success rate for each method. Ideally there would be high quality randomised controlled trials (RCTs) comparing the two approaches but these are not available. While about a third of the studies available for the microsurgery group were RCTs there were no RCTs for retreatment.

Recently we looked at a review that compared microsurgery with implant placement after failed root canal treatment (Dental Elf – 15th Oct 2014) that review also did not have any direct comparisons. Torabinejad the lead author of that review had published a review in 2009 that also looked at surgical and nonsurgical approaches to endodontic treatment. That also suggested more favourable outcomes with endodontic surgery. A commentary on the 2009 review is available in the Evidence-based Dentistry Journal (EBD-2010).